Fittings utilized with flexible hose usually consist of a nipple component which is received within the hose bore and a socket mounted upon the nipple is usually axially restrained upon the nipple and includes a cylindrical portion radially spaced from the nipple and in axial alignment therewith wherein an annular chamber is defined between the nipple and socket receiving the hose material adjacent the hose end.
The hose material located within the annular chamber defined by the nipple and socket may be retained therein by several techniques. For instance, adhesive may be used to bond the hose within the socket, serrations may be formed upon the nipple or the socket inner surface and where helical serrations are used the fitting may be "threaded" upon the hose end, or the diameter of the socket may be reduced by swaging or compression to compress the hose upon the nipple. Also, combinations of the aforementioned techniques may be utilized, such as employing serrations upon the socket inner surface and swaging or crimping the socket on the hose.
In most hose fitting constructions utilizing the aforementioned relationships, a mechanical interconnection exists between the nipple and socket to restrain relative axial movement therebetween. For instance, radial engaging surfaces may be formed upon the socket and nipple, or the socket may be provided with threads which mate with threads defined on the nipple. The socket will include a radial dimension and portion which is homogeneous with the socket cylindrical wall portion, and as the socket includes both radial and axially extending walls and surfaces, significant machining of the socket is normally required, increasing the costs of socket manufacture.
Further, conventional fitting manufacture limits the material from which the fitting is formed in that, in a swaged or crimped socket fitting, the socket must be of a material which is malleable, but high strength cannot be achieved with soft material, and heat treating and stress relief is complicated.
It is an object of the invention to provide a crimpable hose fitting which is economical to manufacture, easy to machine, and permits a wide variety of material selection for the components of the fitting.
A further object of the invention is to provide a hose fitting which is reliable in operation, capable of being used in high pressure applications, and permits selective components to be heat treated and of high strength characteristics without detracting from the crimpability and assembly of the fitting.
Yet an additional object of the invention is to produce a hose fitting formed of a plurality of assembled components wherein several of the components are deformed during assembly and such deformation improves the strength of the assembled product due to work hardening.
An additional object of the invention is to provide a hose fitting utilizing a socket and nipple wherein axial positioning of the socket on the nipple can be readily varied to adapt the fitting to the particular hose and installation, and wherein the fitting is usable with a wide variety of hose materials, such as rubber, neoprene, synthetic plastic, and the like.
In the practice of the invention the fitting basically consists of an inner nipple, a socket which is crimped upon a hose mounted upon the nipple and a cap mechanically interconnected to the socket and the nipple. Also, connection means, such as a nut or adapter is defined upon the nipple for establishing a sealed connection to the associated system component.
Preferably, the nipple is formed of a cylindrical tube which may be of a conventional copper, steel or aluminum tube size. The outer end of the nipple may be flared, or provided with other conventional connection configuration, and a nut, or threaded adapter may be rotatably mounted upon the nipple for establishing connection of the nipple to another fitting, adapter, port, or the like as well known in the conduit system art.
An annular socket is located over the hose in radial alignment with the nipple and an annular cap having an inner diameter slightly greater than the nipple outer diameter is located upon the nipple adjacent the end of the socket, and the outer diameter of the cap is slightly less than the socket inner diameter wherein the cap may be located within the axial confines of the socket. The circumference of the cap includes a groove.
The fitting will be assembled prior to being located upon the hose end, and such assembly consists of positioning the cap as desired upon the nipple, aligning the socket with the cap, and circumferentially deforming the socket end region in radial alignment with the cap inwardly to force the socket material into the cap groove and simultaneously radially compress the cap upon the nipple outer diameter. In this manner a mechanical interconnection is made between the nipple, cap and socket which is mechanically complete and produces a fluid tight metal-to-metal sealed relationship between the nipple and cap, and cap and socket.
After assembly of the nipple, cap and socket, the end of the hose is inserted into the socket and upon the nipple, and upon the end of the hose engaging the cap, or substantially so, the socket can then be radially crimped, or swaged, inwardly upon the hose to complete the interconnection between fitting and hose.
As the nipple, socket and cap are all of simplified configurations readily manufactured by high production techniques, the cost of a flexible hose fitting as aforedescribed is low, yet the fact that the cap and socket are separate components permits a versatility in material selection not available with conventional hose fitting designs and the mode of assembly of the fitting components permits a flexibility not heretofore present in hose fittings.